Serum False-Positive Botulism in Guillain-Barré Syndrome

A 30-year-old man of Guillain-Barre syndrome (GBS) had atypical descending weakness and history of exposure to expired canned meat, which caused confusion with botulism. His serum showed false-positive botulism type B by the standard mouse bioassay. The diagnosis of axonal GBS was based on clinical and electrophysiological evidence. This report highlights the fact that GBS can present descending weakness and serum false-positive botulism.